SIMOREG 6RA70 Siemens DC Master
Variable Speed DC Drive Features
1 Quad or 4 Quad, 18 ADC and 36 ADC active Field

SIMOREG 6RA70 DC Drive Controller complete: (Digital Type)6RA70 DC Master

  • Designed to meet the requirements of NEMA, IEEE, NEC, UL Listed and CSA
  • 6 Pulse SCR (Silicon Controlled Rectifier) Bridge, 1 quad or 4 quad
  • Microprocessor Control Board with 16 bit 38 Mhz high performance multi-tasking microprocessor
  • User interface keypad and digital display
  • Power and interface control board
  • Individual pulse transformers per SCR (comb fire VA rating)
  • R/C snubbers across each SCR
  • Current transformers for current regulator feedback
  • Run/Ready light
  • Plug-in wiring harness between boards
  • Shunt field excitation circuitry with field current loss protection and field economizing (if required for motor heating, programmable)
  • Terminal blocks for incoming/outgoing wiring connections
  • High speed AC Silicon SCR rated power fuses
  • 115VAC phase non-critical control power transformer
  • Power supply transformer
  • Digitally fired burst type SCR gate pulses
  • 1600PIV rated thyristors are standard
  • Built-in A/D converter accepts external reference sources
  • Digital and analog tachometer generator feedback or Voltage feedback speed loop selection
  • Serial communication via RS232 or RS485 serial ports
  • General purpose P-I-D loop for additional regulation modes
  • Freely programmable blocks for mathematical functions
  • Software programming package to aid in start up
  • Peer to Peer Link
  • Tachometer to Voltage Feedback switching
  • Four layer parameter
  • 5 Binary and analog outputs


  • Priority access code protection
  • Minimum speed
  • Maximum speed
  • Linear acceleration
  • Linear deceleration
  • S-Curve rounding
  • Jog and thread speed presets
  • Current Limit
  • Tapered current limit
  • IR compensation for voltage feedback drive application
  • Motor armature current rating
  • Motor field current rating
  • Self turning routine automatically adjust each SIMOREG drive controller to optimum performance matching to motor malfunctions
  • Motor Over speed
  • CEMF crossover voltage (for field weakened speed ranges)


  • Overspeed
  • Field current loss
  • 12t motor overload
  • Instantaneous overcurrent
  • Line tolerance monitoring
  • Phase sequence monitoring
  • Phase loss
  • dv/dt Protection on the SCR’s
  • SCR type high speed AC line fuses
  • DC output fuse on regenerative units
  • Heat sink thermostat
  • Isolated electronics

There are more than 120 diagnostic messages for troubleshooting, including fault and warning indication and memory retention of the last four faults. Some of the diagnostics include:

  • Line voltage out of tolerance
  • Line frequency unstable/out of tolerance
  • Phase loss
  • Motor stalled
  • SCR failure detection and identification
  • Loss of speed of voltage feedback
  • Current overload
  • EEPROM/Microprocessor
  • Quick Stop
  • 8 Channel data storage

Standard LCD Display includes:

  • Speed reference
  • Operating speed
  • Current reference
  • Actual speed
  • Gating angle
  • CEMF
  • Armature voltage
  • CEMF/Speed
  • RMS AC phase to phase voltage
  • All parameter set points (1-941 as apply)
  • Torque direction
  • Operating time
  • Field current reference/field current actual

Siemens Energy & Automation
SIMOREG DC Master Base Drive Operating Instructions